/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing.features;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.Helpers;

import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.Map;
import java.util.Set;

/**
 * Optional features of classes derived from {@code Map}.
 *
 * @author George van den Driessche
 */
// Enum values use constructors with generic varargs.
@SuppressWarnings("unchecked")
@GwtCompatible
public enum MapFeature implements Feature<Map>
{
    /**
     * The map does not throw {@code NullPointerException} on calls such as {@code containsKey(null)},
     * {@code get(null)}, {@code keySet().contains(null)} or {@code remove(null)}.
     */
    ALLOWS_NULL_KEY_QUERIES,
    ALLOWS_NULL_KEYS(ALLOWS_NULL_KEY_QUERIES),
    /**
     * The map does not throw {@code NullPointerException} on calls such as {@code
     * containsValue(null)}, {@code values().contains(null)} or {@code values().remove(null)}.
     */
    ALLOWS_NULL_VALUE_QUERIES,
    ALLOWS_NULL_VALUES(ALLOWS_NULL_VALUE_QUERIES),
    /**
     * The map does not throw {@code NullPointerException} on calls such as {@code
     * entrySet().contains(null)} or {@code entrySet().remove(null)}
     */
    ALLOWS_NULL_ENTRY_QUERIES,
    /**
     * The map does not throw {@code NullPointerException} on any {@code null} queries.
     *
     * @see #ALLOWS_NULL_KEY_QUERIES
     * @see #ALLOWS_NULL_VALUE_QUERIES
     * @see #ALLOWS_NULL_ENTRY_QUERIES
     */
    ALLOWS_ANY_NULL_QUERIES(
            ALLOWS_NULL_ENTRY_QUERIES, ALLOWS_NULL_KEY_QUERIES, ALLOWS_NULL_VALUE_QUERIES),
    RESTRICTS_KEYS,
    RESTRICTS_VALUES,
    SUPPORTS_PUT,
    SUPPORTS_REMOVE,
    FAILS_FAST_ON_CONCURRENT_MODIFICATION,
    /**
     * Indicates that the constructor or factory method of a map, usually an immutable map, throws an
     * {@link IllegalArgumentException} when presented with duplicate keys instead of discarding all
     * but one.
     */
    REJECTS_DUPLICATES_AT_CREATION,

    GENERAL_PURPOSE(SUPPORTS_PUT, SUPPORTS_REMOVE);

    private final Set<Feature<? super Map>> implied;

    MapFeature(Feature<? super Map>... implied)
    {
        this.implied = Helpers.copyToSet(implied);
    }

    @Override
    public Set<Feature<? super Map>> getImpliedFeatures()
    {
        return implied;
    }

    @Retention(RetentionPolicy.RUNTIME)
    @Inherited
    @TesterAnnotation
    public @interface Require
    {
        public abstract MapFeature[] value() default {};

        public abstract MapFeature[] absent() default {};
    }
}
